[llvm] [VPlan] Compute interleave count for VPlan. (PR #149702)

[David Sherwood via llvm-commits]

================
@@ -4229,7 +4229,10 @@ class VPlan {
   /// block with multiple predecessors (one for the exit via the latch and one
   /// via the other early exit).
   bool hasEarlyExit() const {
-    return ExitBlocks.size() > 1 ||
+    return count_if(ExitBlocks,
----------------
david-arm wrote:

Is this changed needed because you're now calling this from places where it wasn't called previously and so has to deal with potentially different CFG? It looks like you're saying having multiple exit blocks is no longer any guarantee that there is an early exit, which is a bit surprising. Do you know why this wasn't required previously?

https://github.com/llvm/llvm-project/pull/149702